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Black Powder Ballistics

I have been shooting black powder revolvers for some time now; I recently bought a chronometer and an accurate scale and decided to do some tests. I compiled my own velocity data and did my own energy calculations. I wanted to share for two reasons. First in case there is some error in my method, people can correct me. Second, just to share the data.

The formula I am using to calculate energy is the one that came with the Chronometer book:
Velocity X Velocity X bullet weight in grains / 450240 = Energy in Ft/lbs

My goal was to compare my Remington .36 cal to my Remington .44 and see how the bullet weight vs velocity variations work out. The .36 had a 6.5 inch barrel while the .44 had a 5.5 inch barrel. Each group listed below is an average of 6 shots. I disqualified any readings that seemed unreasonably high or low. Testing was done under field conditions, not lab conditions, so powder measures may be off by a full grain either way.

It became clear very quickly that for the .36 the highest energy resulted from stuffing the chamber to the max 32 grains. 35 grains represents an over-stuffing and compressing of the powder, which yielded diminishing returns. I only had one size .36 ball (.375) and it was a very tight fit that shaved a ring off the ball as it was seated.

.44 on the other hand required a fair degree of experimentation. Two things seem clear. First, big .44 chambers like to be filled with powder, otherwise there is little benefit over a .36. If you want to save on powder... just get a .36. The second lesson learned was that it is very important to have a very tight seal. I had been using .451 balls which I was able to seat with less effort. The testing shows a significant energy change between .451 and .454. Some Revolvers, have slight differently sized chambers and a .451 may be tight enough. The important thing is that you have a tight seal that allows the pressure to build up behind the ball before it starts to move. The tight seal will be evidenced by a ring of lead being shaved off when you seat the ball and significant resistance when seating.

The energy of these black powder revolvers is quite impressive. It is also worth noting that the original pistols sold by Colt and Remington did not have any instructions as far as how much grain to load into them. It is probably fair to say that soldiers and cowboys loaded them up to the max.

I did some similar tests with modern pistols and got the following results.

Re: Black Powder Ballistics

Nice post!

On the original 44cal designs powder charges:
the Colt Walker was 60gr
the Colt Dragoon was 50grs.
the Colt 1851(steel) and 1860 were 30grs
the Remington 1858(steel) was I think 40-50grs. 40gr being recommended

The brass Confederate framed guns like the 1851 were max of 20-25grs for the 44cal. Late production Pietta brass frame 1851 is recommended at 15grs for the 44cal.

The reason why sometimes the powder charge wasn't shown was because the powder flask spigot came with the gun and pre-sized for the correct volume-metric charge.

I couldn't tell ya what the .36cal charges were. Never got into them.

Just noticed something.. You weighed your powders with a scale.. ....Black powder is to be weighed by volume. 30grs of weight measurement is NOT 30grs of volume-metric measurement, which is proper for blackpowder.

Re: Black Powder Ballistics

Nice to see this kind of data. I was curious myself. I had my 1858 44 Buffalo (12" barrel) out yesterday to play. You gotta love that sulfur smell.

I'm sure you already have the "magic" load for each firearm you shoot, but have you played around yet comparing the pyrodex to Black Powder, or wonder wads to corn meal filler? I wonder how much difference there would be in speeds?

Re: Black Powder Ballistics

Originally Posted by DeadHead

Nice to see this kind of data. I was curious myself. I had my 1858 44 Buffalo (12" barrel) out yesterday to play. You gotta love that sulfur smell.

I'm sure you already have the "magic" load for each firearm you shoot, but have you played around yet comparing the pyrodex to Black Powder, or wonder wads to corn meal filler? I wonder how much difference there would be in speeds?

I have not done any tests with real Black Powder yet, but I sure plan too. I have been shooting muzzle-loaders for a while, but it near impossible to tell what the "magic load" is. That is only possible now that that I have the chronometer and good scale to measure ball weights. Before, my only way to test was to look for penetration into layers of plywood, but that information was too hard to effectively measure and report. You would naturally think that the more powder that you pack into a chamber, the more energy you will get... but it is possible that the powder may not have enough time to burn before the ball exits the barrel. Only with a measured velocity test can we know if we are getting a meaningful return of additional powder added. The tighter fitting ball certainly seems to add to help the equation.

This study will probably take a month or two to complete. I plan to put up a webpage and publish the results. I was searching for this type of detail for a long time but the information is not available... so now I am going to make it available. I am glad that people here are interested in my study and report.

It is significant to note that the .457 ball was not oversized and did not shave off a ring when seated for a very tight fit. My overall testing has shown that a tight fit is a very significant factor that greatly increases velocity. I have ordered a mold to make 200 grain Conical bullets. I am hoping that those will have tighter fit.

The testing of the .31 pocket pistol emphasizes the importance of a tight fit. The .315 ball is seated very easily with almost no effort (no shaving). The .323 ball on the other hand takes great effort and is infact quite painful on the hand as the short lever of the pocket pistol provides very little leverage. The .323 shaved off a nice ring and paid back with increased velocity for the added effort.

For comparison sake, this is the result achieved with my NNA mini revolver loaded with .22 mag

Re: Black Powder Ballistics

tsafa,
Many thanks for your data and your willingness to share it with the rest of us. I currently shoot black powder in the 22 WCF(rifle) , 25-20 (rifle), 38 Special, (pistol and rifle) 44-40 (rifle) and 45 colt (rifle and pistol).

Although I have used Pyrodex and found it to be quite useful, most all of my b.p. shooting is done with Goex, Schuetzen or Swiss. I have found that Swiss works the best in the repeating rifles and will continue to shoot accurately for many more shots than either Goex or Schuetzen before accuracy deteriorates.

In the revolvers with their shorter barrels, the difference is negligible.

All of the cartridges that I shoot with the exception of the 38 Special and 45 Colt, both in a rifle, have had cataloged ballistics. My goal has been to equal or improve upon the original ballistics of the factory loadings.

22 W.C.F. - 45 gr bullet / 13 grs. b.p. 1,500 f.p.s.
This is the only cartridge that I have not been able to equal the factory velocity. 13 Swiss FFFG = 1,420 f.p.s.

Re: Black Powder Ballistics

Originally Posted by w30wcf

tsafa,

38 Special pistol -158 gr bullet / 21.5 grs b.p. - 960 f.p.s.

45 Colt pistol - 250 gr bullet / 40 grs. b.p. - 910 f.p.s.

Thanks for you feedback and data W30wcf. I was particularly interested in your data from 38 Spl and .45 Colt. I calculate energies of 323 ft/lbs and 460 ft/lbs respectively. What model guns were you shooting?